Registration of terrestrial laser scanner data using imagery     

Khalil  Al-Manasir  Clive S.  Fraser 《The Photogrammetric Record》2006,21(115):255-268

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Angular resolution of terrestrial laser scanners   总被引：5，自引：0，他引：5  

Derek D.  Lichti  Sonam  Jamtsho 《The Photogrammetric Record》2006,21(114):141-160

Knowledge of a laser scanner's spatial resolution is necessary in order to prevent aliasing and estimate the level of detail that can be resolved from a scanned point cloud. Spatial resolution can be decoupled into range and angular components. The latter is the focus of this paper and is governed primarily by sampling interval and laser beamwidth. However, emphasis is often placed on one of these—typically sampling interval—as an indicator of resolution. Since both affect the resolution of a scanned point cloud, consideration of only one factor independent of the other can lead to a misunderstanding of a system's capabilities. This will be demonstrated to be inappropriate except under very specific conditions. A new, more appropriate resolution measure for laser scanners, the effective instantaneous field of view (EIFOV), is proposed. It is derived by modelling the shift variance of the equal angular increment sampling process, laser beamwidth-induced positional uncertainty and observed angle quantisation with ensemble average modulation transfer functions (AMTFs). Several commercially available terrestrial laser scanner systems are modelled and analysed in terms of their angular resolution capabilities using the EIFOV.  相似文献   

数字水准仪与精密光学水准仪测量精度比较     

赵瑞  樊钢 《测绘学院学报》2006,(1)

数字水准仪的出现解决了大地测量仪器中水准仪自动读数与记录问题,对当代测量技术产生了积极的影响。文中介绍了如何采用双频激光干涉仪配合45°平面镜检测数字水准仪的方法,对精密光学水准仪和数字水准仪进行综合精度的评定和比较,并对结果进行了分析。  相似文献   

Lidar遥感基本原理及其发展     

隋立春  张宝印 《测绘学院学报》2006,(2)

介绍了航空激光扫描(Airborne laser scanning)或者Lidar遥感信息获取系统的基本原理、系统的组成、数据获取的方法及其步骤;对近数十年来应用激光扫描遥感信息获取地形表面模型方面取得的主要成果、应用现状做了简要回顾和评述;结合GIS和影像融合方法对Lidar遥感技术未来发展趋势进行了展望。  相似文献   

Application of laser strainmenters to the study of earthquake physics     

Grigory I. Dolgikh  Mstislav N. Dubrov  Stanislav G. Dolgikh  Sergei N. Kovalev  Vladimir V. Ovcharenko  Egor A. Savvin  Vladimir A. Chupin  Vyacheslav A. Shvets  Sergei V. Yakovenko 《Acta Geophysica》2006,54(2):187-197

The paper considers possibilities of applying laser strainmeters for the study of earthquake physics. One of laser strainmeters is described. A high efficiency of using the laser strainmeters for the study of earthquakes and their precursors is shown. In records of the spaced laser strainmeters, anomalous deformations propagating from the east to the west with the speed comparable with that of migration of earthquakes were found.  相似文献   

太空垃圾实时监测系统建立可行性分析     

魏二虎  严韦 《测绘信息与工程》2007,32(2):1-4

介绍了太空垃圾监测及清除工作现状,分析了现有监测太空垃圾的雷达技术、激光技术及激光雷达技术的可行性,以STK软件模拟分析太空垃圾运动轨迹,得出了太空垃圾实时监测系统的可实现方法和建议。  相似文献   

Analysis of rock drainage and cooling experiments for underground cryogenic LNG storage     

Sung-Soo Cha  Kang-Kun Lee  Gwang-Ok Bae  Dae-Hyuck Lee  Nicolas Gatelier 《Engineering Geology》2007,93(3-4):117-129

Hydrogeological monitoring was conducted around a pilot cavern for underground cryogenic LNG (Liquefied Natural Gas) storage. The monitoring was mainly focused on the operation of a drainage and recharge system. After the operation of the drainage system commenced, the drainage rate decreased rapidly in the initial stages and then decreased gradually. Hydrogeological monitoring revealed that the rock drainage system operated effectively. During drainage, the water table was maintained below the cavern roof. The recharge for ice-ring formation was performed in two phases. The first phase involved the cessation of pumping in downward-drainage holes and the second involved the closure of upward boreholes. Since the water table was maintained below the cavern roof, artificial recharge was planned at first. However, it was not implemented due to heavy rainfall in the recharge stage. On the basis of hydrogeological monitoring and hydraulic tests, it was found that the fractures above the roof and on the right wall of the pilot cavern mainly affected seepage into the cavern and thermal variation due to the storage of liquid nitrogen. Thermal variation was examined by the thermometers installed around the pilot cavern. The cooling and thawing processes reveal the characteristics of thermal distribution in the rock and the 0 °C isotherm. The cooling phase lasted for six months, and the 0 °C isotherm progressed in time after the injection of liquid nitrogen into the cavern. The isotherm propagated up to about 4 m from the floor and the sidewall of the cavern and about 3 m from the cavern roof. The cooling rate of the rock mass above the cavern roof was lower than that of the other cavern sides due to the gaseous space in the upper part of the containment. The fractures were analyzed and considered for thermal modeling. A two-dimensional finite element analysis was performed to compare the field monitoring at the pilot cavern. The numerical modeling shows the distance between the ice ring and heat transfer pattern of the fractures around the pilot cavern. The propagation of the measured and calculated 0 °C isotherm reveals that the water-conveying joint on the right wall might affect thermal propagation through a thermal pipe.  相似文献   

Laser Scanning的基本原理及其应用前景     

WANG Ren    XU Qing 《测绘学院学报》2007,(Z1)

首先介绍了激光测距仪的发展历程,针对应用领域的不同,分别对3维激光成像仪和机载/星载激光测高仪的测量原理进行了阐述,并分别介绍了两种激光测距仪的工作流程以及数据处理流程,最后对两种激光测距仪的应用范围进行了阐述,并把两种激光测距技术和普通摄影测量进行了比较,指出了激光测距技术相对于普通摄影测量的优点,即高精度性、穿透性、实时性。  相似文献   

基于BP神经网络的三维激光测高数据拟合方法     

武晓忠张菊清  聂建亮 《解放军测绘研究所学报》2007,27(4):22-24

针对三维激光测高拟合问题，本文采用BP神经网络进行拟合，该方法可以有效地消除或减弱数据中的系统误差影响，提高计算精度。实际算例证明，在数据无粗差情况下，BP神经网络的内符合与外符合精度优于传统的二次曲面拟合的精度。  相似文献   

一种应用于城市区域的自适应形态学滤波方法   总被引：5，自引：0，他引：5  

梁欣廉  张继贤  李海涛 《遥感学报》2007,11(2):276-281

数学形态学滤波是从激光雷达数据中识别地面点、创建数字高程模型的一种重要方法,在应用中取得了较好的效果,但也具有一些明显不足。在分析现有方法优劣及城市地形特点的基础上,提出一种应用于城市环境的自适应形态学滤波算法。该方法采用分层识别策略：首先通过分割得到地面主体部分;之后利用正规化高度值寻找其余地面区域;最后估计地物覆盖区域地面点取值。采用三个不同分辨率、不同地形/地物特点的数据集进行了实验,结果表明该方法能有效识别地面和地物点,并解决了窗口尺寸限制、粗差误判等问题。  相似文献